Series 3 Whats this part called?

I'm looking to replace the inside of the front left wheel arch, as shown in photograph... its rotted out to the point its not even attached. I'm struggling to find the part as I'm not sure what its called, any help would be much appreciated.
Land rover Series 3 88", 1972.

[Edit] I have found a galvanised version! https://www.paddockspares.com/mrc6082galv-rhd-mudshield-fr-1969-lights-wings-lh-galvanised.html

Mud shield <<---*link

I got mine from here but since then looks like the thickness gone down but still thicker than most